Talk:PageRank

Removed

Google uses an automated web spider called Googlebot to actually count links and gather other information on web pages.

It is by no means clear that the counting can be said to be done by Googlebot, and it is not intuitively a spidering operation, more likely a feature of the database to which the spidering software stores its flies. Therefore this needs a citation to be in the article. Clearly what parts of the Google infrastructure are called "Googlebot" is up to Google, however if it extends too far, the description needs to be changed. All the best: Rich Farmbrough, 13:25, 11 August 2014 (UTC).

Examples are Wrong

• It's not clear what does the value 0.5 represents
• The sum(i, M_i,j) is never 1
• I think columns/rows have been messed up. Comments mention that M_i,j represents link from j to i, but if you run a clear example, e.g, the following:

everything links to A which means A is an important page, and A links to C, thus C is important as well.

   M = np.array([
       [1, 1, 1],  # * -> A
       [0, 0, 0], 
       [1, 0, 0]   # A -> C
   ])
  print(pagerank(M, 0.001, 0.85)) 
  array([[0.61536926],  
         [0.28131799],
         [0.10331275]])

B should be last but its second. Am I missing something?

I'm not sure which version of the algorithm this edit was referring to, but I've been working with it and it works; in this case, [1, 1, 1] should be impossible because A cannot link to itself. A links to C would be [0, 0, 1] on the A row if [A, B, C], and A links to both B and C would be [0, 1, 1]. I'm also not sure what the call to `pagerank(..., 0.001, ...)` is meant to do, since `0.001` doesn't make sense as the number of iterations (I'm guessing it would iterate once).

--D.g.lab. (talk) 16:31, 10 April 2021 (UTC)

I'm also not sure what was meant by the sum of (i, M_i, j) is 1 since half those variable names don't exist in the code. It could be said that the sum of every column in the matrix is 1?

The sum of the result vector, called v in the code, should also be approximately 1, I believe, since it contains percentages.

--D.g.lab. (talk) 16:39, 10 April 2021 (UTC)

Variables lack clear names

It's already difficult enough to understand as it is, why not clarify the variable names and add comments, as in any good code? For example:

   def pagerank(matrix, num_iterations: int = 100, damping: float = 0.85):
       size = matrix.shape[1]
       res_vector = [1/size] * size
       M_hat = (damping * matrix + (1 - damping) / size)
       for i in range(num_iterations):
           res_vector = M_hat @ res_vector # matrix multiplication
       return res_vector

Also, notice the lines in the article:

   v = np.random.rand(N, 1)
   v = v / np.linalg.norm(v, 1)

these insert random numbers in the multiplication vector. However, as far as I understand, this vector is supposed to start initially as `1/number_of_pages` (1/size) for each of its elements, which could be re-written

   v = [1/N] * N

or, using the new varible names,

   res_vector = [1/size] * size

According to this video on YouTube: Linear Algebra – Introduction to PageRank (4:21 timestamp).

I'm unsure why this was like this, so I'm not editing the page; however, if someone can confirm, the initial method seems "way too complicated" and there's no explanation for it. --D.g.lab. (talk) 16:31, 10 April 2021 (UTC)

site:example.com

😐site:example.com 2A00:F41:4828:36B6:0:4B:5D7E:4801 (talk) 23:52, 24 February 2022 (UTC)

reference 25 is old

the article states:'PageRank continues to be the basis of googles....'[25] reference 25 is over 10y old so it does not prove anything. 213.247.64.239 (talk) 14:32, 18 January 2023 (UTC)

@213.247.64.239

actual text from the article:

'While just one of many factors that determine the ranking of Google search results, PageRank continues to provide the basis for all of Google's web-search tools.' 213.247.64.239 (talk) 14:33, 18 January 2023 (UTC)

Google doesn't disclose the details of its ranking systems, but they have affirmed that PageRank remains one of the many signals they use. While there might be a more recent reference, it wouldn't be very precise. They don't disclose those kinds of details. While this article could use some clean up, it's not inaccurate in saying that Google still uses the algorithm. Michael Martinez (talk) 15:01, 18 January 2023 (UTC)

Google recently added new documentation that confirms PageRank is still used in their ranking systems although it has evolved since the original paper (in unspecified ways).Michael Martinez (talk) 13:01, 25 April 2023 (UTC)

"Supplemental Result" listed at Redirects for discussion

The redirect Supplemental Result has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2024 April 25 § Supplemental Result until a consensus is reached. Utopes _{(talk / cont)} 05:12, 25 April 2024 (UTC)

Merge PageRank algorithm in biochemistry

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

To not merge; no support with stale discussion; either improve linking or take to AfD were alternative (unsupported) proposals. Klbrain (talk) 12:09, 19 November 2024 (UTC)

---

Most of the content on PageRank algorithm in biochemistry is redundant to material here, including a confusing and incomplete explanation of how PageRank works. It also hasn't had any meaningful updates since 2014. The small amount of material that actually pertains to PageRank's biochem applications should be merged here. Apocheir (talk) 01:56, 23 June 2024 (UTC)

I'm not sure merging the articles is the right thing to do. PageRank is based on citation analysis. To date no one has suggested merging PageRank into the Citation analysis - Wikipedia article. And I don't think that would be appropriate, either. While I agree there is some redundancy between the two PageRank articles, there are similar redundancies across Wikipedia. Cross-linking them and minimizing the duplication is the better solution in my opinion. Michael Martinez (talk) 03:08, 23 June 2024 (UTC)

I would recommend just taking this to AFD. InfiniteNexus (talk) 08:45, 26 June 2024 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Citation possibly required in lead

Hello, in the lead of this article the claim 'It is named after both the term "web page" and co-founder Larry Page' is made without a citation.

As a reader I wanted a source for this claim when I first saw it, and I was able to find one in the body of the text when the same claim is repeated. The editing guidelines suggest that to some extent citations to claims that are repeated and sourced in the body of the article can be avoided, however in this case it seems likely that it needs to be cited in the lead as well.

I do not have a great intuition about Wikipedia's norms for this kind of thing so I wanted to confirm that others would want a citation there before making an edit Least Informed Nerd (talk) 01:52, 10 February 2026 (UTC)

"Topic-Sensitive PageRank" listed at Redirects for discussion

The redirect Topic-Sensitive PageRank has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 October 9 § Topic-Sensitive PageRank until a consensus is reached. Jay 06:20, 9 October 2026 (UTC)

"TSPR" listed at Redirects for discussion

The redirect TSPR has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 October 9 § TSPR until a consensus is reached. Jay 06:20, 9 October 2026 (UTC)